1. Field of Invention
The invention relates to an electronic device including a mechanical module and a method for obtaining alternative characteristic values for the electronic device.
2. Description of Related Art
Known information technology (IT) devices, such as facsimile machines and printers, produce print output onto a recording sheet by driving components or units thereof using motors, such as DC motors and pulse motors. Ideal drive conditions of components of an IT device, such as voltage and current, are determined at the design stage of the IT device, based on results of tests performed for individual prototype components or overall prototype devices, as well as by considering possible variations of loads applied due to, for example, environmental conditions.
For example, for carriages of dot printers and ink-jet printers in which print heads move across a recording sheet, the drive conditions, such as voltage and current, may be determined to allow for variations due to environmental conditions, after moving loads are measured using, for example, a sprint scale.
After the drive conditions are determined, the measurements are carried out again using an actual device to confirm whether the device works as designed. If the device does not work properly, the device conditions are changed, for example, by increasing voltage or current. The optimum drive conditions obtained through tests are adopted as the ultimate drive conditions for the device.
For example, Japanese Laid Open Patent Publication No. 55-71196 discloses a method in which time required for a motor to start operating is measured by applying predetermined current. Based on measurement results, impact or degree of loads applied to the motor is determined by values of the current as alternative characteristic values of the loads. This method may be effective at the research and development stage, or design stage where the current may be easily changed, but not at the product manufacturing or repairing stage where current or voltage values are difficult to change. Consequently, the confirmation made at the product manufacturing (shipment) or repairing stage is to inspect whether an IT device actually works with the determined design values.
It is difficult to know how high an operational margin (allowance for loads applied by the setting current/voltage) of each product is, from the above-described confirmation or inspection made at the time of shipment or repair. When low-margin products are placed in the market, the products may possibly malfunction at customers site, as components of the products are worn out during usage and the drive loads applied are increased.
When the products are not assembled properly, for example, a component is missing, loads applied to the products may vary. As described above, it is only confirmed at the product manufacturing or repairing stage whether products work properly with the design values. Therefore, differences of the loads between the actual products and the design value are not confirmed. In addition, allowing for a margin of operations of the products, voltage and current tend to be set to a greater values. Due to such settings, the products may seemingly work properly during the confirmation or inspection at the manufacturing or repairing stage, even when the products are poorly assembled. If problems attributable to, for example, poor assembly are be found after the products are subjected to all processes of assembly or repair, the products have to be disassembled and re-assembled to find out causes of the problems, resulting in unfavorable quality and manufacturing controls.